The present invention relates to a semiconductor manufacturing technique and more particularly to a technique useful in its application to the improvement in the quality of a semiconductor device.
As examples of semiconductor devices having a semiconductor chip with a semiconductor integrated circuit formed thereon, further having bump electrodes (e.g., solder balls) as external terminals and a wiring board which supports the semiconductor chip, there are known CSPs (Chip Scale Packages) or BGAs (Ball Grid Arrays).
As to the former CSP there has been developed a CSP which is small-sized and thin-walled, like the chip size or slightly larger than a semiconductor chip, and wherein a semiconductor chip is mounted on one side, i.e., on a chip bearing surface, of a wiring board, the chip bearing surface side being sealed with resin by molding to form a sealing portion.
As a technique for improving the CSP manufacturing efficiency and thereby attaining the reduction of cost there has been developed a block molding method.
According to the block molding method, a multi device substrate is used on which plural device areas corresponding to thin film wiring boards are formed in a partitioned and contiguous manner and are sealed with resin by molding while being covered together. After the sealing with resin, dicing is performed for division (formation of individual pieces) into each device area.
This semiconductor device manufacturing method using such a block molding method, as well as the structure of the semiconductor device are disclosed, for example, in Japanese Unexamined Patent Publication No. 2000-124163 or Hei 11 (1999)-214588.
In the above publication 2000-124163 there is described a countermeasure to peeling at an interface between a substrate and a molding resin which exfoliation is caused by an internal stress developed between the resin and the substrate.
As described in the above publication, the case where an internal stress is created due to a difference in thermal expansion coefficient between the substrate and the molding resin is based on the premise that the strength of the substrate is so high as to generate a force resistive to a relative deformation (difference in volume change) between the molding resin and the substrate.
As the cause of occurrence of a relative deformation between the molding resin and the substrate there is shrinkage on curing of the molding resin, in addition to the aforesaid difference in thermal expansion coefficient. The shrinkage on curing of the molding resin indicates a decrease of volume caused by a bonding force based on a crosslinking reaction when a polymer which constitutes the resin cures on heating.
Thus, the molding resin and the substrate give rise to a relative deformation due to a difference in thermal expansion coefficient or shrinkage of the resin on curing. However, by adopting a substrate which is flexible enough to follow up the deformation of the molding resin, it is possible to keep the internal stress between the substrate and the molding resin very low.
Moreover, by adopting a thin film substrate it is possible to attain the reduction in thickness of the semiconductor device. Further, polyimide is superior in heat resistance, anti-hygroscopic property and adhesion to the molding resin and is very suitable as a substrate material for a semiconductor device.
However, the use of a flexible material as the substrate material gives rise to the problem that peeling is apt to occur at the substrate-molding resin interface due to a stress induced by a blade at the time of dicing.
Particularly, when up cutting is performed as in FIG. 11(d) or 11(e), a force is exerted in a direction to peel off the substrate from the molding resin with a blade in a cutting portion, so that the problem of substrate peeling is apt to occur.
At a corner portion of each device area where dicing lines cross each other, stress is easily concentrated at a vertex of the corner portion. Besides, at and around the corner portion damage is given to the substrate twice from the blade and thus the corner portion is particularly apt to cause the problem of substrate exfoliation.
It is an object of the present invention to provide a semiconductor device and a method of manufacturing the same capable of preventing the exfoliation between a molding resin and a substrate and improving the quality of the semiconductor device.
The above and other objects and novel features of the present invention will become apparent from the following description and the accompanying drawings.
As to typical modes included in the present invention, a brief description will be given below.
In one aspect of the present invention there is provided a semiconductor device comprising a thin film wiring board which supports a semiconductor chip, with cutout portions being formed in peripheral edge portions of the thin film wiring board, and which is deformable following shrinkage on curing of a molding resin, a conductive member for connecting each surface electrode on the semiconductor chip with the thin film wiring board, a sealing portion which is constituted by the molding resin and which seals the semiconductor chip and the conductive member with resin, the sealing portion having a sealing body portion formed on a chip bearing surface of the thin film wiring board and sealing end portions located in the cutout portions of the thin film wiring board, and a plurality of bump electrodes as external terminals formed on the side opposite to the chip bearing surface of the thin film wiring board.
According to this construction, since the sealing end portions as a part of the sealing portion are mainly disposed in the peripheral edge portion of the semiconductor device, a blade mainly cuts the molding resin at the time of dicing after block molding.
Consequently, it is possible to prevent peeling between the sealing portion and the thin film wiring portion, i.e., peeling between the molding resin and the thin film wiring board, during dicing. As a result, it is possible to improve the quality of the semiconductor device obtained.
In another aspect of the present invention there is provided a semiconductor device comprising a thin film wiring board which supports a semiconductor chip, with cutout portions being formed in corner portions of the thin film wiring board, and which is deformable following shrinkage on curing of a molding resin, a conductive member for connecting each surface electrode on the semiconductor chip with the thin film wiring board, a sealing portion which is constituted by the molding resin and which seals the semiconductor chip and the conductive member with resin, the sealing portion having a sealing body portion formed on a chip bearing surface of the thin film wiring board and sealing end portions located in the cutout portions of the thin film wiring board, and a plurality of bump electrodes as external terminals formed on the side opposite to the chip bearing surface of the thin film wiring board.
According to this construction, since sealing end portions as a part of the sealing portion are located at corner portions of the semiconductor device, the blade cuts only the molding resin at corner portions where peeling of the substrate is apt to occur during dicing.
During dicing, therefore, it is possible to prevent peeling of the substrate, i.e., peeling between the molding resin and the thin film wiring board, at corner portions, so that it is possible to improve the quality of the semiconductor device.
In a further aspect of the present invention there is provided a semiconductor device comprising a thin film wiring board which supports a semiconductor chip, with thin-walled portions being formed in peripheral edge portions of the thin film wiring board, and which is deformable following shrinkage on curing of a molding resin, a conductive member for connecting each surface electrode on the semiconductor chip with the thin film wiring board, a sealing portion which is constituted by the molding resin and which seals the semiconductor chip and the conductive member with resin, the sealing portion having a sealing body portion formed on a chip bearing surface of the thin film wiring board and sealing end portions bonded to the thin-walled portions of the thin film wiring board, and a plurality of bump electrodes as external terminals formed on the side opposite to the chip bearing surface of the thin film wiring board.
In a still further aspect of the preset invention there is provided a semiconductor device manufacturing method comprising the steps of providing a thin film wiring board which is deformable following shrinkage on curing of a molding resin and which has a plurality of partitioned device areas, mounting semiconductor chips respectively on the device areas, connecting surface electrodes on the semiconductor chips with corresponding electrodes in the device areas by means of conductive members, sealing the semiconductor chips and the conductive members with resin so as to cover the plural device areas in a lump on the chip bearing surface side of the thin film wiring board, thereby forming a sealing portion, and causing a cutting blade to advance toward the sealing portion from the thin film wiring board side to divide the wiring board device area by device area in accordance with a down cutting method.
In a still further aspect of the present invention there is provided a semiconductor device manufacturing method comprising the steps of providing a thin film wiring board which is deformable following shrinkage on curing of a molding resin and which has a plurality of partitioned device areas, mounting semiconductor chips respectively on the device areas, connecting surface electrodes on the semiconductor chips with corresponding electrodes in the device areas by means of conductive members, sealing the semiconductor chips and the conductive members with resin so as to cover the plural device areas in a lump on the chip bearing surface side of the thin film wiring board, thereby forming a sealing portion, and dividing the thin film wiring board device area by device area with a cutting blade in two stages in the first stage of which the blade advances in a direction parallel to one arrangement direction of the device areas on the thin film wiring board and in the second stage of which the blade advances in a direction perpendicular thereto.
In a still further aspect of the present invention there is provided a semiconductor device manufacturing method comprising the steps of providing a thin film wiring board which is deformable following shrinkage on curing of a molding resin and which has a plurality of device areas partitioned by partition lines, the partition lines serving also as cutting allowances, mounting semiconductor chips respectively on the device areas, connecting surface electrodes on the semiconductor chips with corresponding electrodes in the device areas by means of conductive members, sealing the semiconductor chips and the conductive members with resin so as to cover the plural device areas in a lump on the chip bearing surface side of the thin film wiring board, thereby forming a sealing portion, and causing a cutting blade to advance from the thin film wiring board side and move along the cutting allowances to divide the wiring board device area by device area.
In a still further aspect of the present invention there is provided a semiconductor device manufacturing method comprising the steps of providing a thin film wiring board which is deformable following shrinkage on curing of a molding resin and which has a plurality of device areas partitioned by partition lines, with a plurality of through holes being formed in the partition lines, mounting semiconductor chips respectively on the device areas, connecting surface electrodes on the semiconductor chips with corresponding electrodes in the device areas by means of conductive members, sealing the semiconductor chips and the conductive members with resin so as to cover the plural device areas in a lump on the chip bearing surface side of the thin film wiring board, while allowing the molding resin to get into the through holes in the thin film wiring board, and causing a cutting blade to advance from the thin film wiring board side to cut the wiring board along the through holes formed in the partition lines and thereby divide the wiring board device area by device area.
In a still further aspect of the present invention there is provided a semiconductor device manufacturing method comprising the steps of providing a thin film wiring board which is deformable following shrinkage on curing of a molding resin and which has a plurality of device areas partitioned by partition lines, with through holes being formed in corner portions of the partition lines, mounting semiconductor chips respectively on the device areas, connecting surface electrodes on the semiconductor chips with corresponding electrodes in the device areas by means of conductive members, sealing the semiconductor chips and the conductive members with resin so as to cover the plural device areas in a lump on the chip bearing surface side of the thin film wiring board, while allowing the molding resin to get into the through holes in the thin film wiring board, and causing a cutting blade to advance from the thin film wiring board side to cut the wiring board along the through holes formed in the corner portions of the partition lines and thereby divide the wiring board device area by device area.
In a still further aspect of the present invention there is provided a semiconductor device manufacturing method comprising the steps of providing a thin film wiring board which is deformable following shrinkage on curing of a molding resin and which has a plurality of device areas partitioned by partition lines, with thin-walled portions being formed in the partition lines, mounting semiconductor chips respectively on the device areas, connecting surface electrodes on the semiconductor chips with corresponding electrodes in the device areas, sealing the semiconductor chips and the conductive members with resin so as to cover the plural device areas in a lump on the chip bearing surface side of the thin film wiring board, while allowing the molding resin to be placed on the thin-walled portions, and causing a cutting blade to advance from the thin film wiring board side to cut the wiring board along the thin-walled portions formed in the partition lines and thereby divide the wiring board device area by device area.